1. Field of the Invention
The invention relates to a method for detecting a tire module, detached from the inner face of a tire, for vehicles.
2. Discussion of Background Information
Tire modules which are provided with transponders are used in tires, in particular in tire sensors for truck tires, for various tasks. These include, in particular tire identification with which an automobile manufacturer can, inter alia, detect in a quick and automated fashion which tire works has supplied a specific tire and on which vehicle the tire was fitted. Other tasks are generally monitoring of the air pressure, measurement of the temperature or the measurement of mechanical stress states in the tire. Modern transponders are composed of an electronic component or electronic chip in which sensor elements can be arranged, and of an antenna which is connected to this electronic component. An example of such a transponder is disclosed by DE 102 43 441 A1.
In systems up to now, the sensors have been screwed to the rim with a clamping belt or attached to the valve seat.
A sensor module which is arranged on the rim can damage the tire on its inner face if it becomes detached from its mount and lies in an uncontrolled fashion in the tire. Sometimes, the electronics of the sensor continue to function for a certain time despite the high accelerations which occur and they also still continue to display a measured value to the driver for this tire. Nevertheless, sharp edges can actually result in damage to the tire without the fault being noticeable from the outside.
The new sensor modules for monitoring tire pressure are bonded into the tire, on the inner face of the tire. As a result, these tire modules are subjected to higher stresses than is the case in the wheel modules which are mounted with a steel belt on the rim or are attached to the valve seat. The risk of the tire modules becoming detached from the inner face of the tire may be greater with this method of attaching sensor modules. It is therefore important to detect a detached tire module as early as possible.